Yes, with boundaries worth understanding: a records based opinion from a registered Australian vet is legitimate professional advice, supported by AVA policy on second opinions. What an online opinion cannot legally or sensibly do is prescribe medication or replace physical examination by your treating vet; it informs your decisions rather than taking over the case.
For surgical questions specifically, records based review is not a compromise format: the x-rays, the history and the quote are the information, and they travel perfectly. Where a fresh physical examination would genuinely change the answer, an honest reviewer says exactly that.
How to spot a good service: a named, registered vet whose credentials you can check, relevant to your question, a surgeon for surgical decisions; a written product you can show your own vet; clear pricing before you pay; and plain statements of what the service does not do. Anonymous panels, instant answers to complex questions, and opinions that come bundled with something to sell you are the flags in the other direction.
Send what your vet said and quoted. A veterinary surgeon reads it and comes back to you with what they can do and what it would cost, before you pay anything. A written second opinion is from $250.
Send the case, hear back from a surgeon with what they can do and what it costs, and only pay if you go ahead.